Low frequency variability of fishing resources, climate, and ocean

The apparently synchronous variation of fisheries catch time-series at the decadal scale, mainly from the Pacific Ocean and parts of the Atlantic, as well as their empirical relationship to climatic fluctuations, permits assuming the existence of global scale processes forcing the abundance of the fisheries resources. Given its relevance for management, we conducted an exploratory analysis of the variability of catch of the world's main fisheries and their possible relationship to the environmental changes of the ocean and atmosphere. The FAO database for 1950–2000 was used to obtain landing time-series. Three hundred and sixty-one catch-series were selected, taking in account their historical average and the unequivocal identity of the target species; 131 from the Pacific, 191 from the Atlantic, and 39 from the Indian Ocean. The patterns of variation were identified by using two methods of cluster analysis: tree clustering and K-means. Three patterns were identified, for both the Pacific and Atlantic and only two for the Indian Ocean. Principal components analysis of 12 climatic indexes permitted recognizing three main modes, corresponding mostly to the tropical Pacific, extratropical Pacific, and Atlantic Oceans. An analysis of the long-term variation showed a dominant pattern over the 50-year period, that has been related as the remote synchrony hypothesis fish marine catch.